USB Bridge Controller CH341


CH341 is a USB converter chip, which converts USB to serial UART interface, printer interface, parallel port interface, and common 2/4 synchronize serial communication interfaces etc. In UART mode, CH341 provides UART transmit enable, UART receive ready rate control signals and so on, and common MODEM interface signals, to expand UART interface of computer or upgrade common serial communication devices to USB directly. In LPT mode, CH341 provides a standard USB print port compatible with USB-related specifications and the Windows operating system for upgrading a print port printer directly to the USB. In parallel port mode, CH341 provides an 8-bit parallel interface in EPP mode or MEM mode for input and output data directly without a microcontroller/DSP/MCU. In addition, CH341B/F/A support commonly used synchronous serial interfaces such as 2-wire interface (SCL line, SDA line) and 4-wire interface (CS line, SCK/CLK line, MISO/SDI/DIN Line, MOSI/SDO/DOUT line), etc.


2.1. Introduction

  • Full speed USB device interface, USB 2.0 compatible.
  • Supports 5V and 3.3V power supply.
  • Optional: customize the vendor ID, product ID, serial number, etc. via an external low-cost serial EEPROM.
  • Low cost, convert the original serial port peripheral devices, the original print port printer, and the original parallel port peripheral devices to USB directly.
  • RoHS compliant SOP-28, SSOP-20 and QFN28 lead-free package.
  • Only compatible with the applications, and cannot be absolutely the same. 2.2. UART
  • Emulate standard UART interface, used to upgrade the original serial devices or expand additional UART via USB.
  • Original UART applications are totally compatible without any modification.
  • Hardware full duplex serial UART interface, integrated transmit-receive buffer, supports communication baudrates varies from 50bps to 2Mbps.
  • Supports 5, 6, 7 or 8 data bits and 1 or 2 stop bits, supports odd, even, none, mark, space parity.
  • Supports UART transmit enable, UART receive ready rate control signals and so on, and common MODEM interface signals.
  • Provides further RS232, RS485, RS422 interface, etc. through external voltage conversion chip.
  • Supports access to the CH341 external serial EEPROM memory in UART communication. 2.3. Print Port
  • Standard USB print port for upgrading the original print port printer, compatible with the relevant USB specifications.
  • Compatible with Windows/Linux/MACOS and so on, and the application is fully compatible.
  • Supports various standard print port printers, optional low speed printing and high speed printing.
  • Supports two-way communication of the IEEE-1284 specification and supports one-way and two-way transmission of printers. 2.4. Parallel Port
  • Two modes are available: EPP mode and MEM mode.
  • EPP provides signals such as AS#, DS# and WR# etc. Similar to EPP V1.7 or EPP V1.9.
  • The MEM mode provides signals such as A0, RD# and WR# etc. Which is similar to the memory read/write mode. 2.5. Synchronous serial port
  • FlexWireTM technology, enables flexible 2-wire to 5-wire synchronous serial ports through software.
  • As a Host/Master host, it supports common synchronous serial interfaces such as 2-wire and 4-wire.
  • The 2-wire interface provides two signal lines SCL and SDA, and supports 4 transmission speeds.

Development Information Datasheet: CH341DS1.PDF Drivers: 1.CH341SER.EXE(Windows driver, supports WIN10/WIN8/WIN7/XP etc.) 2.CH341SER_ANDROID.ZIP(Android application) 3.CH341SER_LINUX.ZIP(Linux driver) 4.CH341SER_MAC.ZIP(MAC OS driver) Schematic/PCB: CH341PCB.ZIP